Administration instrument for medical use

ABSTRACT

An administration instrument for medical use performs injection of a drug solution with stability and with great reliability. The administration instrument includes a needle that does not wobble, thereby alleviating physical and mental pain of the administration patient. The structure includes an injection button that is pressed at an angle that is not parallel to the needle with respect to a direction in which the needle is inserted into the skin. Thus, it is possible to prevent the force of pressing the injection button from being transmitted in a direction of insertion of the needle so that the needle is inserted deeper into the skin than the initial insertion of the needle, thereby achieving administration under a stable state.

TECHNICAL FIELD

The present invention relates to administration instruments for medicaluse, which are used to administer drug solutions such as insulin.

BACKGROUND ART

Conventionally, administration instruments for medical use havefrequently been used in administering drug solutions such as insulin orhormone preparations. Generally, such an administration instrument formedical use includes a needle, a syringe body, and an injection button,which are almost aligned, thereby pushing an injection out of a drugsolution cartridge that is housed in the syringe body in a directionthat is parallel to the needle by the injection button. FIGS. 24 and 25show two typical devices of the prior art

In FIG. 24, reference numeral 201 denotes a body of an administrationinstrument for medical use (hereinafter, also referred to as a syringebody), numeral 202 denotes an injection that is sucked in the body 201of the administration instrument for medical use, numeral 203 denotes aninjection button, numeral 204 denotes a needle, and numeral 205 denotesa plunger of a part that is connected to the injection button 203 anddirectly pushes the injection 202 out of the syringe.

The syringe body 201 contains the injection 202. When the injection isto be administered, the needle 204 is inserted into the skin, and theinjection button 203 is pressed, thereby forcing the injection 202 outof the body 201 of the administration instrument for medical use. Theamount of the injection 202 administered is decided by adjusting theamount of press onto the injection button 203 is pressed.

That is, an administrator (patient) pushes the injection button 203 tomove the internal plunger 205, thereby forcing the injection 202 out ofthe needle 204. The amount sliding of the plunger 205 that slides willdecide the amount of the injection that is administered. Theadministrator (patient) decides the amount of the injection 202 to beadministered, inserts the needle 204 into a desired position on theskin, and presses the injection button 203, thereby completing theinjection. When the needle 204 is inserted into the skin, theadministrator (patient) must decide the amount of the insertion of theneedle into the skin based on his/her past experiences or the like.

Most of the administration instruments for medical use that are used forself-administration are mechanical or pen types, as shown in FIG. 24.Since the injection button is pushed in the same direction as theinitial insertion of the needle into the skin in such instruments, thestate of the administration becomes unstable. On the other hand, asshown in FIG. 25, to solve the above-mentioned problem, recentlycontrived is an administration instrument for medical use including aportion which touches the skin at the administration near the needle,thereby deciding the positions of the needle and the skin to provide thestability of administration.

In FIG. 25, numeral 301 denotes a body of the administration instrumentfor medical use, numeral 303 denotes an injection button, numeral 304denotes a needle, numeral 306 denotes a skin touch portion that istouched on the skin in administrating an injection using thisconventional administration instrument for medical use, numeral 307denotes a drug solution cartridge, and numeral 302 denotes an injectionin the drug solution cartridge 307.

At the administration, the needle 304 is inserted into the skin with theskin touch portion 306 touching the skin, and the injection button 303is pressed to force the injection 302 out of the drug solution cartridge307. The amount of the administration is decided by adjusting the amountof pressing onto the injection button 303 is pressed.

In most cases of the conventional administration instrument for medicaluse, the needle is attached to the instrument body immediately beforethe actual administration of the injection, and a decided amount of adrug solution is administered to a human body after performingpreliminary pressing (hereinafter, also referred to as air removal) toprevent air from being injected with the injection.

In the conventional administration instrument for medical use, theexternal view of which is shown in FIG. 24, when administering the drugsolution, it is possible to push the injection button or theadministration button also in a state where the needle is not attachedto the administration instrument body. Accordingly, the injection buttonor the administration button may be inadvertently pushed, therebycausing a problem.

Further, in the case of the conventional administration instrument formedical use, a doctor conducts a diagnosis to give instructions as tothe amount of an injection to be administered and the interval of theadministration, and the administrator performs self-administration ofthe drug solution in accordance with these instructions, whilemanagement of the amount of the injection administered and the intervalof the administration is left to the administrator himself/herself. Inaddition, the doctor regularly conducts the diagnosis, and newly decidesthe amount of the injection to be administered and the interval of theadministration on the basis of the result of the diagnosis, the amountof the injection that was administered, and the interval of theadministration, thereby giving new instructions.

Conventionally, the mechanical administration instruments for medicaluse, as shown in FIGS. 24 and 25, have been often used forself-administration, while some instruments that are provided withelectronic devices have been recently contrived.

A typical structure of this instrument is shown in FIGS. 26 and 27.Further, FIG. 28 shows a block diagram with a microprocessor shown inthe center. FIG. 26 is a front view of the instrument, and FIG. 27 is atop view thereof partially illustrated in cross section.

In FIG. 26, numeral 403 denotes a syringe body, numeral 401 denotes aneedle, numeral 404 denotes a display section, numeral 405 denotes adial for setting the amount of an injection to be administered, andnumeral 406 denotes an injection button.

In FIG. 27, a cartridge 407 containing an injection 426 is placed in thesyringe body 403. The administrator pulls out the injection button 406before the injection. When the injection button 406 is pulled out, asleeve 418 and a nut 412 also slide together with the injection button406 in the same direction as the injection button 406.

By the sliding of the sleeve 418, a spline portion 416 of the sleeve 418is coupled to a spline portion 417 of the administration amount settingdial 405. The coupled portion of the sleeve 418 and the plunger 408 isnot fixed in the sliding direction but fixed in the rotationaldirection. The coupled portion of the sleeve 418 and the nut 412 is notfixed in the rotational direction but fixed in the sliding direction.

As a result, when the administrator rotates the administration amountsetting dial 405, the sleeve 418 is rotated, and the plunger 408 isaccordingly rotated, whereby the plunger 408 is slid by a thread that isprovided on the inner circumference of the nut 412 and a thread that isprovided on the outer circumference of the plunger 408. The amount ofthe injection to be administered is decided depending on the amount ofthe sliding of the plunger 408. When the injection button 406 is notpulled out, the sleeve 418 and the administration amount setting dial405 are not coupled, whereby even when the administration amount settingdial 405 is rotated, the plunger 408 will not move.

The administrator rotates the administration amount setting dial 405 todecide the amount of the injection to be administered, insets the needle401 in a position where the administration is to be performed, and thendepresses the injection button 406, thereby completing the injection.When the injection has been completed, the injection button 406, thesleeve 418, and the nut 412 are slid in a direction in which they aredepressed. In order to detect that the injection button 406, the sleeve418, and the nut 412 have been slid, a projection 420 is provided on thesleeve 418, and a switch 413 that is turned on or off by the projection420 is fixed on the body 403.

The switch 413 is turned on when the injection button 406 is pulled out,while the switch is turned off when the injection button 406 isdepressed. The completion of the injection is detected by observing thestate of the switch 413. As a means for judging the completion of theinjection according to the state of the switch 413, a microprocessor425, as shown in FIG. 28, or the like, is employed, and the completionis judged by judging a conduction state of the switch 413.

Here, numeral 417 denotes a spline portion of the setting dial 405,numeral 419 a and 419 b denote optical sensors, numeral 414 denotes aliquid crystal display, numeral 415 denotes a board, numeral 421 denotesa rotational plate, and numeral 421 a denotes a rotational plate slit.In FIG. 28, numeral 422 denotes a memory of the microprocessor 425,numeral 423 denotes a calendar, numeral 424 denotes a clock, and numeral404 denotes a display interface with the liquid crystal display 414.

FIG. 29 is an enlarged view illustrating a part for detecting completionof the injection. When setting the amount of the injection to beadministered is to be set, the administration amount setting dial 405and the sleeve 418 are rotated. The amount of the injection administeredis decided depending on the amount of motion of the plunger 408, whichis caused by rotation of the administration amount setting dial 405.Therefore, a method is employed in which the amount of the injectionadministered is detected by detecting the rotation of the administrationamount setting dial 405 and the sleeve 418, and the amount of therotation. Here, numeral 416 denotes a sleeve spline portion, and numeral417 denotes a setting dial spline portion.

For example, as shown in FIG. 30, the rotational plate 421 that rotatestogether with the administration amount setting dial 405 is provided,and the slits 421 a are formed on the rotational plate 421 as shown inFIG. 31, and two optical sensors 419 a and 419 b are provided atpositions where light crosses the slits 421 a. When the administrationamount setting dial 405 is rotated, the rotational plate 421 is alsorotated, and the slits 421 a that are provided on the rotational plate421 pass through or interrupt the light of the optical sensors 419 a and419 b. Since the optical sensors 419 a and 419 b output an ON signal oran OFF signal depending on the amount of light, it is possible to detectthe rotation and the amount of the rotation in accordance with the ON orOFF signal outputted from the optical sensors 419 a and 419 b.

Here, the reason why two optical sensors 419 a and 419 b are employed isbecause the amount of the injection administered is increased ordecreased according to the direction of the rotation of theadministration amount setting dial 405. The rotation direction is judgedon the basis of a phase difference of ON or OFF of the outputs from thetwo optical sensors 419 a and 419 b, and the amount of the injection tobe administered is detected by counting the number of ON or OFF of theoutputs from the optical sensors 419 a and 419 b. As described above,the microprocessor 425 or the like is employed as shown in FIG. 32 asthe means of judging the rotation direction based on the phasedifference of the outputs from the optical sensors 419 a and 419 b, anddetecting the amount of the injection to be administered by counting thenumber of ON or OFF of the outputs from the optical sensors 419 a and419 b.

Further, by providing the microprocessor 425 and the memory 422,recording or display of the time and date of the completion of theinjection is also performed. In addition, using, for example, opticalsensors 419 a and 419 b, sensors that utilize a switch or the like arecontrived.

However, in the conventional administration instrument as shown in FIG.24, since the needle 204 is inserted into the skin at theadministration, and the injection 202 is administered with pressing theinjection button 203 in the same direction as that of the insertion ofthe needle 204 into the skin, the needle 204 would be inserted deeperinto the skin from the state where the needle is initially inserted intothe skin, thereby increasing the pain of the patient at theadministration.

Further, also at the administration in a case where the administrationinstrument for medical use is provided with the skin touch portion 306as shown in FIG. 25, the needle 304 is inserted into the skin with theskin touch portion 306 touched on the skin, and then the injection 302is administered by pressing the injection button 303 in the samedirection as the insertion of the needle 304 into the skin. Therefore,also in this case, the above-mentioned problem that the needle 304 wouldbe inserted into the skin deeper from the state where the needle isinitially inserted into the skin occurs because, even when the skintouch portion 306 is provided, the actual skin has the elasticity andthus the needle 304 would be inserted into the skin deeper by a force ofthe actual pressing of the injection button 303.

To avoid this problem, it is necessary to fix the arm by which theinjection button 303 is pressed in midair or by some method with careduring the administration. However, it is quite difficult when theadministration of the drug solution is performed by the patienthimself/herself.

When the needle is inserted into the skin deeper during theadministration, the pain of the patient would be increased, which is notonly distressing both physically and mentally but in some cases mayexert many influences upon the body of the administrator (patient),resulting in a hazardous condition to his/her life.

Further, in the conventional administration instrument for medical useas shown in FIG. 24 or 25, since the needle is not always uniform andthe length of the needle is different depending on the type, the amountof the needle that is inserted into the skin varies and, in some cases,the failure of the injection or the burden of pain becomes large, andserious influences may be exerted upon the body of the administrator(patient), resulting in a hazardous condition to the life.

Further, in the conventional administration instrument for medical useas shown in FIG. 24, it is possible to press the injection button or theadministration button even when the administrator forgets aboutattaching the needle to the administration instrument body. Therefore,following problems arise.

One of the problems is as follows. When the injection button or theadministration button is pressed without the needle attached, the drugsolution may be leaked out of the end portion of the syringe opposite tothe injection button or the administration button or the drug solutionmay flow backward and leak toward the injection button or theadministration button, like a leaking drug solution 221 a or a backwardflowing drug solution 221 b in FIG. 33, or, as shown in FIG. 34, theglass tube itself containing the drug solution obtains cracks 227 or isruptured due to a force that is generated by the pressing of theinjection button or the administration button, and broken, whereby thedrug solution leaks outside.

Further, also in cases where two types of drug solutions are mixed or adrug and a drug solution are dissolved, such as growth hormonepreparations, it is necessary to perform the mixture after the needle isattached to the instrument. Accordingly, when the administrator forgetsabout attaching the needle, it is impossible to achieve the mixture, andfurther the back-flow or leakage of the drug solution, or the crackingor rupture of the glass tube of the drug solution cartridge adverselyoccurs as described above. Many of the above-mentioned problemsfrequently occur, particularly when the patient performs theadministration by himself/herself.

Further, in the case of the conventional administration instruments formedical use as shown in FIGS. 24 to 27, the risk of accidents may be lowwhen the doctor or the nurse administers the drug solution, but when thepatient by himself/herself performs the administration, an operation ofremoving air from the syringe which is always performed before theadministration may be forgotten if he/she does not always keep it inmind. When the air removal is forgotten, the human bodies of some peoplemay be affected seriously, possibly resulting in a hazardous conditionto life.

Further, in the conventional administration instrument for medical useas shown in FIG. 26 or 27, the amount of the injection that has beenadministered can be displayed on the electronic display unit, but theamount of the injection, the date, and the time at the air removaloperation that is always performed before the administration are alsorecorded in the memory 422, whereby the available space of the memory422 is uselessly reduced. In addition, since the amount of the injectionat the air removal operation is also displayed together with theessential injection amount, when the doctor checks the result of thediagnosis and the past administration history of the administrator(patient) to decide the future remedy, there is a risk that the doctormakes a wrong diagnosis. If the doctor makes such a wrong diagnosis, thebody of the administration (patient) may be seriously affected, and ahazardous condition to the life may be produced.

SUMMARY OF THE INVENTION

The present invention is made to solve the above-mentioned problems ofthe conventional administration instruments, and has for its object toprovide an administration instrument for medical use that can inject adrug solution safely and with great reliability.

More specifically, the present invention is made to solve the problemsof the conventional pen-type or mechanical instrument as shown in FIG.24 or 25, and has for its object to provide an administration instrumentfor medical use that prevents the needle from being inserted into theskin more than required even when the injection button is pressed at theadministration as well as performs the administration in a stable state.

Further, the present invention is made to solve the problems of theconventional pen-type or mechanical instrument as shown in FIG. 24 or25, and has for its object to provide an administration instrument formedical use with the reliability, which keeps the length of the needlethat is inserted into the skin uniform regardless of the type of theneedle that is used by the administrator (patient), to provide a stableadministration state, thereby minimizing the failure of the injection orthe burden of pain resulting from the injection.

Further, the present invention is made to solve the problems of theconventional pen-type instrument as shown in FIG. 24, and has for itsobject to provide an administration instrument for medical use whichprevents leakage or back-flow of the drug solution, or cracking orrupture of the glass tube containing the drug solution, as well asprovides high reliability and safety to the user.

Further, the present invention is made to solve the problems of theconventional instruments as shown in FIGS. 24 to 27, and has for itsobject to provide an administration instrument for medical use whichalways informs and makes the administrator aware of air removal beforethe administration so as to prevent the administrator from forgettingthe air removal operation that should be performed before theadministration, as well as which is safe and easy to use.

Furthermore, the present invention is made to solve the problems of theconventional instrument which is provided with the electronic device asshown in FIG. 26 or 27, and has for its object to provide anadministration instrument for medical use which disables to record theamount of the injection administered, the date, and the time at the airremoval operation which is performed by the administrator at theadministration in the memory 422, thereby keeping a reliableadministration history.

To attain the above-mentioned object, according to a first aspect of thepresent invention, there is provided an administration instrument formedical use including: an injection button for administering aninjection, which is depressed by an administrator of the injection; anda depressing force transmission unit for transmitting an injectionbutton depressing force to a plunger of a drug solution cartridge thatcontains the injection at an angle that is not parallel to alongitudinal direction of a needle, thereby enabling administration ofthe injection by pressing the injection button at an angle that is notparallel to a direction of insertion of the needle.

Therefore, a force that is applied when the injection button is pressedis not transmitted in such a manner as to insert the needle into theskin deeper than the initial insertion of the needle into the skin,thereby not increasing physical and mental pains of the administeringpatient.

According to a second aspect of the present invention, in theadministration instrument for medical use of the first aspect, thedepressing force transmission unit includes: a rack which extends in thesame direction as that of the depression of the injection button; afirst gear which engages with teeth formed on one side of the rack in alongitudinal direction; a second gear which engages with the first gear;and a movable piece which has teeth engaging with the second gear on oneside thereof in a direction perpendicular to the rack extendingdirection, and the movable piece presses the plunger of the drugsolution cartridge due to the pressing operation of the injectionbutton.

Therefore, a force that is applied when the injection button is pushedis not transmitted in such a manner as to insert the needle into theskin deeper than the initial insertion of the needle to the skin,thereby not increasing the physical and mental pains of theadministering patient.

According to a third aspect of the present invention, the administrationinstrument for medical use of the first aspect includes: an injectionamount setting unit for setting an amount of the injection to beadministered.

Therefore, at the administration, only pressing of the injection buttonis required without looking at a scale that indicates the injectionamount, thereby alleviating loads of the administering patient.

According to a fourth aspect of the present invention, in theadministration instrument for medical use of the third aspect, theinjection amount setting unit includes: a sleeve which is integratedwith the plunger, and passes through and engages with the movable piece;and an administration amount adjustment knob which is attached to thesleeve on a side opposite to the plunger, and moves the movable piecewithin the drug solution cartridge forward or backward by theadministrator changing the rotational direction.

Therefore, when the amount of the injection to be administered ispreviously set by operating the administration amount adjustment knob,only pressing of the injection button is required at the actualadministration, without looking at the administration amount scale,thereby alleviating the load of the administering patient.

According to a fifth aspect of the present invention, the administrationinstrument for medical use of first aspect includes: an injection buttonreturn unit for returning the injection button to its original positionwhen the finger that has pressed the injection button is taken off afterthe administration.

Therefore, there is no need for the administering patient to return theinjection button after the administration to perform the administrationagain, thereby alleviating the load of the administered patient.

According to a sixth aspect of the present invention, in theadministration instrument for medical use of the fifth aspect, theinjection button return unit comprises a spring that is sandwichedbetween an end surface of the rack opposite to the injection button andan inner surface of the administration instrument for medical use.

Therefore, by only adding a simple structure, it is possible toeliminate the need for the administered patient to return the injectionbutton after the administration to perform the administration again,thereby alleviating the load of the administered patient.

According to a seventh aspect of the present invention, in theadministration instrument for medical use of the first aspect, a skintouch portion which is touched on the skin at the injection is providedon the same side as a surface of the body of the administrationinstrument for medical use, on which the needle is located.

Therefore, it is possible to administer the drug solution under a stablestate in which the needle does not wobble.

According to an eighth aspect of the present invention, there isprovided an administration instrument for medical use including: a skintouch portion that touches the skin of an administrator to stabilize anadministration state at administration of a drug solution; a positionvariable unit for variably changing a position of the skin touchportion; and a skin touch area variable unit for variably changing askin touch area of the skin touch portion.

Therefore, even when the size of the needle is not uniform and thelength of the needle is different depending on the type, it is possibleto always make the dimension of the needle that is inserted into theskin constant, thereby eliminating the variations in the amount of theneedle that is inserted into the skin. Further, by variably increasingthe fixture area of the skin touch portion under the administrationstate, it is possible to apply the administration instrument for medicaluse to the skin of the administrator (patient) under a state in whichthe instrument is held with stability, thereby reducing a failure of theinjection or loads of the pain, providing a reliable administrationinstrument for medical use, and supporting the remedy decided by thedoctor with greater reliability.

According to a ninth aspect of the present invention, in theadministration instrument for medical use of the eight aspect, the skintouch position variable unit comprises a mating fixing unit for matingand fixing the skin touch portion to the body of the administrationinstrument for medical use stepwise at a desired position in alongitudinal direction of a needle.

Therefore, by securely fixing the skin touch position variable unit at adesired position, it is possible to always make the dimension of theneedle that is inserted into the skin constant, thereby eliminating thevariations in the amount of the needle that is inserted into the skin.

According to a tenth aspect of the present invention, in theadministration instrument for medical use of the eighth aspect, the skintouch area variable unit comprises a skin touch width adjustment unitfor variably changing an area of a skin touch width by manually slidinga skin touch width adjustment piece including a part of a surface of theskin touch portion.

Therefore, it is possible to easily change/increase the fixture area ofthe skin touch portion by a manual operation in the administrationstate, and to apply the administration instrument for medical use to theskin of the administrator (patient) under a stable state where theinstrument is held with stability, thereby reducing a failure of theinjection or loads of the pain, providing a reliable administrationinstrument for medical use, and supporting the remedy decided by thedoctor with greater reliability.

According to an eleventh aspect of the present invention, there isprovided an administration instrument for medical use including: anadministration operation inhibit unit for inhibiting an administrationoperation that is activated by pressing an injection button or anadministration button when a needle is not attached to theadministration instrument.

Therefore, it is possible to prevent that, when the injection button orthe administration button is pressed without the needle being attachedto the instrument, the drug solution leaks from the end portion of theinstrument opposite to the injection button or the administrationbutton, or the drug solution flows back toward the injection button orthe administration button and leaks outside, or the glass tube thatcontains the drug solution itself is cracked or ruptured and broken dueto a pressure that is generated by pressing the injection button or theadministration button and accordingly the drug solution in the tubeleaks outside.

According to a twelfth aspect of the present invention, in theadministration instrument for medical use of the eleventh aspect, theadministration operation inhibit unit inhibits an operation of a plungerthat forces a drug solution out of the needle when the button operationis performed in a case where the needle is not attached to theadministration instrument.

Therefore, when the injection button or the administration button ispressed without the needle being attached to the instrument, it ispossible to prevent that the plunger is operated, and accordingly thedrug solution leaks from the end portion of the instrument opposite tothe injection button or the administration button, the drug solutionflows back toward the injection button or the administration button andleaks outside, or the glass tube that contains the drug solution itselfis cracked or ruptured and broken due to a pressure that is generated bypressing of the injection button or the administration button and thusthe drug solution leaks outside.

According to a thirteenth aspect of the present invention, in theadministration instrument for medical use of the eleventh aspect, theadministration operation inhibit unit includes: a needle attachmentdetection unit for detecting whether the needle is attached to theadministration instrument or not, whereby it detects that the needle isnot attached to the administration instrument, to inhibit the operationof the injection button or the administration button.

Therefore, when the injection button or the administration button ispressed without the needle being attached to the instrument, it ispossible to prevent that the drug solution leaks from the end portion ofthe instrument opposite to the injection button or the administrationbutton, the drug solution flows back toward the injection button or theadministration button and leaks outside, or the glass tube that containsthe drug solution itself is cracked or ruptured and broken due to apressure that is generated by pressing of the injection button or theadministration button and accordingly the drug solution leaks outside.

According to a fourteenth aspect of the present invention, theadministration instrument for medical use of the thirteenth aspectincludes: a plunger driving unit for driving the plunger by an operationof the injection button or the administration button, and the needleattachment detection unit engaging with the plunger driving unit whenthe needle is not attached to the administration instrument to inhibitthe operation of the injection button or the administration button.

Therefore, it is possible to detect that the needle is not attached tothe administration instrument and to suppress the operation of theinjection button or the administration button with a simple structure,whereby when the administrator forgets about attaching the needle to theinstrument and presses the injection button or the administrationbutton, it is possible to prevent that the drug solution leaks from theend portion of the instrument opposite to the injection button or theadministration button, or the drug solution flow back toward theinjection button or the administration button and leaks outside, or theglass tube that contains the drug solution itself is cracked or rupturedand broken due to a pressure that is generated by pressing of theinjection button or the administration button and accordingly the drugsolution leaks outside.

According to a fifteenth aspect of the present invention, in theadministration instrument for medical use of the fourteenth aspect, aresin unit that is integral with the needle contacts the detection unitwhen the needle is attached to the administration instrument.

Therefore, it is possible to make a compact administration instrumentfor medical use that can easily detects the presence or absence of theneedle.

According to a sixteenth aspect of the present invention, in theadministration instrument for medical use of the fifteenth aspect, aresin unit that is integral with the needle is separated from thedetection unit when the needle is removed from the administrationinstrument.

Therefore, it is possible to make a compact administration instrumentfor medical use with a simple detection mechanism.

According to a seventeenth aspect of the present invention, in theadministration instrument for medical use of the fourteenth aspect, theplunger driving unit includes: an injection button for administering aninjection, which is depressed by an administrator of the injection; arack which extends in the same direction as that of the depression ofthe injection button, and has a cut-away engagement portion in a part; afirst gear which engages with teeth formed on one side of the rack inits longitudinal direction; and a second gear which engages with thefirst gear and teeth that are formed on the plunger in its longitudinaldirection, the needle attachment detection unit includes: an eject leverwhich is located in parallel to the plunger, and has an L-shaped endportion that is sandwiched between the drug solution cartridge and theneedle on one end, and a cut-away engagement portion that is formed at aposition corresponding to the engagement portion of the rack; and aspring member that pulls the eject lever toward the tip of the needle,and when the needle is not attached to the instrument with the L-shapedend portion being sandwiched, the engagement portions of the eject leverand the plunger engage with each other due to a tension of the springmember, thereby inhibiting the operation of the injection button or theadministration button.

Therefore, it is possible to detect that the needle is not attached tothe administration instrument to suppress the operation of the injectionbutton or the administration button with a simple structure, whereby itis possible to prevent when the administrator forgets about attachingthe needle to the instrument and presses the injection button or theadministration button, that the drug solution leaks from the end portionof the instrument opposite to the injection button or the administrationbutton, or the drug solution flows back toward the injection button orthe administration button and leaks outside, or the glass tube thatcontains the drug solution itself is cracked or ruptured and broken dueto a pressure that is generated by pressing of the injection button orthe administration button and accordingly the drug solution leaksoutside.

According to an eighteenth aspect of the present invention, there isprovided an administration instrument for medical use that isconstructed in such a manner that, when a drug solution cartridge is tobe placed in the administration instrument body, the drug solutioncartridge cannot be housed normally in the administration instrumentbody without a needle being attached thereto.

Therefore, it is possible to prevent, when the administrator forgetsabout attaching the needle to the instrument and presses the injectionbutton or the administration button, that the drug solution leaks fromthe end portion of the instrument opposite to the injection button orthe administration button, or the drug solution flows back toward theinjection button or the administration button and leaks outside, or theglass tube that contains the drug solution itself is cracked or rupturedand broken due to a pressure that is generated by pressing the injectionbutton or the administration button and accordingly the drug solutionleaks outside.

According to a nineteenth aspect of the present invention, in theadministration instrument for medical use of the eighteenth aspect,plural drug solutions are mixed or a drug and a drug solution aredissolved and mixed, and the mixture cannot be performed in theadministration instrument body unless a needle is attached thereto.

Therefore, when the needle is not attached to the administrationinstrument body, the drug solution cartridge cannot be housed in theadministration instrument body and accordingly the drug solutions cannotbe mixed, whereby it is possible to prevent leakage or flow-back of thedrug solution, or cracking or rupture of the glass tube that containsthe drug solution.

According to a twentieth aspect of the present invention, in theadministration instrument for medical use of the nineteenth aspect, whenthe drug solution cartridge is to be placed in the body of theadministration instrument, a rear rubber part of the drug solutioncartridge cannot slide within the drug solution cartridge withcontacting apart of the administration instrument, unless a needle isattached to the instrument.

Therefore, when the needle is not attached to the administrationinstrument body, the drug solution cartridge cannot be housed in theadministration instrument body and accordingly the drug solutions cannotbe mixed, whereby it is possible to prevent leakage or flow-back of thedrug solution, or cracking or rupture of the glass tube that containsthe drug solution.

According to a twenty-first aspect of the present invention, in theadministration instrument for medical use of the nineteenth aspect, inthe drug solution cartridge, different drugs or drug solutions areloaded in a front half of the cartridge to which the needle is attachedand a rear opposite half of the cartridge, respectively, the front halfof the cartridge has a larger diameter part, the inner diameter of whichis larger than the inner diameter of the remaining parts, the rearrubber part is provided on an end surface that is opposite to an endsurface of the drug solution cartridge to which the needle is attached,and by depressing the rear rubber part into the drug solution cartridge,a separation rubber that partitions the front half and the rear half ofthe cartridge is moved to the larger diameter part, thereby mixing thedrugs or drug solutions.

Therefore, when the needle is not attached to the instrument, the rearrubber portion of the drug solution cartridge cannot slide within thedrug solution cartridge with contacting a part of the administrationinstrument, and the drug solution cartridge cannot be housed in theadministration instrument body when the needle is not attached to theadministration instrument and accordingly the drug solutions cannot bemixed, whereby it is possible to prevent leakage or back-flow of drugsolution, or cracking or rupture of the glass tube that contains thedrug solution.

According to a twenty-second aspect of the present invention, theadministration instrument for medical use of the twenty-first aspectincludes: a dissolution piece which is fixed to the administrationinstrument body and pushes the rear rubber part of the drug solutioncartridge by sliding the cartridge within the administration instrumentbody and attaching the same to the body.

Therefore, it is possible to perform mixture of drug solutions withinthe drug solution cartridge with a simple structure that is added to theadministration instrument body.

According to a twenty-third aspect of the present invention, in theadministration instrument for medical use of the eighteenth aspect, aretractable door is provided at a position on the administrationinstrument body in which the drug solution cartridge is loaded when thedrug solution cartridge is to be loaded in the administration instrumentbody.

Therefore, the operation of loading the drug solution cartridge can beeasily performed.

According to a twenty-fourth aspect of the present invention, in theadministration instrument for medical use of the eighteenth aspect, aneedle attachment detection unit for detecting whether the needle isattached to the administration instrument or not is provided between theneedle and the administration instrument body.

Therefore, it is possible to make a compact administration instrumentfor medical use that can easily detect the presence or absence of theneedle.

According to a twenty-fifth aspect of the present invention, in theadministration instrument for medical use of the twentieth aspect, asliding piece for sliding the drug solution cartridge and housing thesame into the administration instrument body is fixed in synchronizationwith the needle attachment detection unit which detects that the needleis attached to the drug solution cartridge.

Therefore, by only adding a simple structure, it is possible to housethe drug solution cartridge in the administration instrument bodysmoothly and reliably when the needle is attached, and securely maintainthe state of the drug solution cartridge being housed in the instrument.

According to a twenty-sixth aspect of the present invention, in theadministration instrument for medical use of the twenty-fifth aspect,the needle attachment detection unit is provided under the sliding piecein parallel to the sliding piece, except for an L-shaped end portionthat is sandwiched between the needle and the drug solution cartridge atattachment of the needle, an eject knob is provided which fits intoopenings that are formed on the sliding piece and the needle attachmentdetection unit by a depressing urge force, and the openings are formedso that positions of the openings of the sliding piece and the needleattachment detection unit are the same in a state where the needle isnot attached yet, while the positions of the openings are different fromeach other in a state where the needle attachment detection unit isshifted by attaching the needle to the instrument.

Therefore, by only adding a simple structure, it is possible to smoothlyand reliably house the drug solution cartridge in the administrationinstrument body when the needle is attached to the instrument, andsecurely maintain the state of the cartridge being housed therein.

According to a twenty-seventh aspect of the present invention, there isprovided an administration instrument for medical use including an airremoval announcement unit for urging an administrator to perform an airremoval operation for removing air that remains within a drug solutioncabin of the administration instrument before injection.

Therefore, it is possible to make the administrator (patient) aware ofair removal and prevent occurrence an accident that the administratorforgets the air removal operation that is to be performed before theadministration and then a serious influence is exerted upon the body ofthe administrator (patient), possibly resulting in a hazardous state forthe life, thereby providing a safe and easy-to-use administrationinstrument for medical use.

According to claim 28 of the present invention, in the administrationinstrument for medical use of claim 27, the air removal announcementunit displays a text, a symbol, or a figure, which urges theadministrator to perform the air removal operation, as well as outputsvoices which urge the administrator to perform the air removaloperation.

Therefore, it is possible to display a text, a symbol, or a figure thaturges an air removal operation to make the administrator (patient) awareof the air removal, and prevent occurrence of an accident that theadministrator forgets about the air removal operation that is to beperformed before the administration, and accordingly a serious influenceis exerted upon the body of the administrator (patient), possiblyresulting in a hazardous state for the life, thereby providing a safeand easy-to-use administration instrument for medical use.

According to a twenty-ninth aspect of the present invention, in theadministration instrument for medical use of the twenty-seventh aspect,the air removal announcement unit includes: a first switch for detectingremoval of a body cap that is attached over the body of theadministration instrument for medical use to which a needle is attached;a air removal display signal generation unit for generating a displaysignal for the text, the symbol, or the figure that urges theadministrator to perform the air removal operation when the first switchdetects that the body cap is removed; and a display unit for displayingthe display signal for the text, the symbol, or the figure that urgesthe air removal operation, thereby displaying the text, the symbol, orthe figure that urges the administrator to perform the air removaloperation when the body cap attached over the body of the administrationinstrument for medical use to which the needle is attached is removed.

Therefore, it is possible to display a text, a symbol, or a figure thaturges an air removal operation when the body cap is removed, to make theadministrator (patient) aware of the previous air removal and preventoccurrence of an accident that the administrator forgets the air removaloperation that is to be performed before the administration and then aserious influence is exerted upon the body of the administrator(patient), possibly resulting in a hazardous state for the life, therebyproviding a safe and easy-to-use administration instrument for medicaluse.

According to a thirtieth aspect of the present invention, in theadministration instrument for medical use of the twenty-seventh aspect,the air removal announcement unit includes: a second switch fordetecting that the drug solution cartridge has been loaded into the bodyof the administration instrument for medical use; an air removal displaysignal generation unit for generating a display signal for a text, asymbol, and a figure that urges the administrator to perform an airremoval operation at a time when the second switch detects that the drugsolution cartridge has been loaded into the body of the administrationinstrument for medical use; and a display unit for displaying thedisplay signal for the text, the symbol, and the figure that urges theair removal operation, thereby displaying the text, the symbol, and thefigure that urges the administrator to perform the air removal operationwhen the drug solution cartridge is loaded into the body of theadministration instrument for medical use.

Therefore, it is possible to display a text, a symbol, or a figure thaturges an air removal operation when the drug cartridge has been loaded,to make the administrator (patient) aware of the previous air removal,and prevent occurrence of an accident that the administrator forgets theair removal operation that is to be performed before the administrationand then a serious influence is exerted upon the administrator(patient), possibly resulting in a hazardous state for the life, therebyproviding a safe and easy-to-use administration instrument for medicaluse.

According to a thirty-first aspect of the present invention, in theadministration instrument for medical use of the twenty-seventh aspect,the air removal announcement unit includes: a first switch for detectingremoval of the body cap which is attached over the body of theadministration instrument for medical use to which the needle isattached; an air removal audio signal generation unit for generating anaudio signal that urges the administrator to perform an air removaloperation when the first switch detects the removal of the body cap; anda speaker for outputting voices in accordance with the audio signal thaturges the air removal operation, thereby outputting the voices that urgethe administrator to perform the air removal operation when the body capis removed.

Therefore, it is possible to output voices that urge an air removaloperation when the body cap has been removed, to make the administrator(patient) aware of previous air removal and prevent occurrence of anaccident that the administrator forgets an air removal operation that isto be performed before the administration and then a serious influenceis exerted upon the body of the administrator (patient), possiblyresulting in a hazardous state for the life, thereby providing a safeand easy-to-use administration instrument for medical use.

According to a thirty-second aspect of the present invention, in theadministration instrument for medical use of the twenty-seventh aspect,the air removal announcement unit includes: a second switch fordetecting that the drug solution cartridge has been loaded into the bodyof the administration instrument for medical use; an air removal audiosignal generation unit for generating an audio signal that urges theadministrator to perform an air removal operation when the second switchdetects that the drug solution cartridge has been loaded in theadministration instrument for medical use; and a speaker for outputtingvoices in accordance with the audio signal that urges the air removaloperation, thereby outputting voices that urge the administrator toperform the air removal operation when the drug solution cartridge hasbeen loaded in the body of the administration instrument for medicaluse.

Therefore, it is possible to output voices that urge an air removaloperation when the drug solution cartridge has been loaded into theinstrument, to make the administrator (patient) aware of the previousair removal, and prevent occurrence of an accident that theadministrator forgets an air removal operation that is to be performedbefore the administration, and then a serious influence is exerted uponthe body of the administrator (patient), possibly resulting in ahazardous state for the life, thereby providing a safe and easy-to-useadministration instrument for medical use.

According to a thirty-third aspect of the present invention, there isprovided an administration instrument for medical use including: aneedle contact detection unit for detecting that a needle is touchingthe skin; an injection completion detection unit for detecting thatinjection has been completed; an injection amount detection unit fordetecting an amount of the injection administered; an injection amountrecording unit for recording the amount of the injection administered;and a control unit for controlling the injection amount detection unitand the injection amount recording unit to record the amount of theinjection administered only when the injection completion detection unitdetects that the injection has been completed and the needle contactdetection unit detects that the needle is touching the skin.

Therefore, it is possible to detect that the injection has beencompleted and, at the same time, record the detected amount of theinjection only when the needle is touching the skin, to keep only thehistory at the actual administration with reliability, without keepingthe history at the air removal, thereby solving various problems suchthat the amount of the injection at the air removal operation which isalways performed before the administration is also recorded in thememory, and thus the available space of the memory unit is uselesslyreduced, or the doctor erroneously judges that administration has beenperformed though it is not actually performed, in checking the result ofthe diagnosis and the past administration history of the administrator(patient) and deciding the future remedy, and accordingly a seriousinfluence is exerted upon the body of the administrator (patient), whichcould result in a state hazardous to the life, whereby it is possible toprovide an administration instrument for medical use that can supportthe remedy decided by the doctor with greater reliability.

According to a thirty-fourth aspect of the present invention, theadministration instrument for medical use of the thirty-third aspectincludes: a calendar unit for generating a present date information; aclock unit for generating a present time information; and the controlunit detecting that the injection has been completed and, at the sametime, recording the date and the time of the completion of theinjection.

Therefore, it is possible to detect that the injection has beencompleted and, at the same time, record the detected injection amountand the date and time of the injection only when the needle is touchingthe skin, to securely keep only the history at the actual administrationwithout keeping the history at the air removal, thereby preventingvarious problems such that the amount of the injection and the date andtime at the air removal operation, which is always performed before theadministration, are also recorded in the memory, and thus the availablespace of the memory unit is uselessly reduced or the doctor erroneouslyjudges that administration has been performed though it is not actuallyperformed, in checking the result of the diagnosis and the pastadministration history of the administrator (patient) and deciding thefuture remedy, and accordingly a serious influence is exerted upon thebody of the administrator (patient), which could result in a statehazardous to the life, whereby it is possible to provide anadministration instrument for medical use that can support the remedydecided by the doctor with greater reliability.

According to a thirty-fifth aspect of the present invention, theadministration instrument for medical use of the thirty-third aspectincludes: a display unit for displaying an injection amount in settingan amount of the injection to be administered, and an injection amountthat is recorded when the injection has been completed.

Therefore, it is possible to detect that the injection has beencompleted and, at the same time, display the detected amount of theinjection only when the needle is touching the needle, to securely keeponly the history at the actual administration without keeping thehistory at the air removal, thereby solving various problems such thatalso the amount of the injection at the air removal operation that isalways performed before the administration is displayed, then the doctorerroneously judges that administration has been performed though it isnot actually performed, in checking the result of the diagnosis and thepast administration history of the administrator (patient) and decidingthe future remedy, and accordingly a serious influence is exerted uponthe body of the administrator (patient), which could result in a statehazardous to the life, whereby it is possible to provide anadministration instrument for medical use that can support the remedydecided by the doctor with greater reliability.

According to a thirty-sixth aspect of the present invention, in theadministration instrument for medical use of the thirty-fifth aspect,the display unit displays the date and the time, in addition to theinjection amount that is recorded at the completion of the injection.

Therefore, it is possible to detect that the injection has beencompleted and, at the same time, display the detected injection amountand the date and time only when the needle is touching the skin, tosecurely keep only the history at the actual administration withoutkeeping the history at the air removal, thereby solving various problemssuch that also the amount of the injection and the date and time at theair removal operation that is always performed before the administrationare displayed, then the doctor erroneously judges that administrationhas been performed though it is not actually performed, in checking theresult of the diagnosis and the past administration history of theadministrator (patient) and deciding the future remedy, and accordinglya serious influence is exerted upon the body of the administrator(patient), which could result in a state hazardous to the life, wherebyit is possible to provide an administration instrument for medical usethat can support the remedy decided by the doctor with greaterreliability.

According to a thirty-seventh aspect of the present invention, in theadministration instrument for medical use of the thirty-third aspect,the needle contact detection unit includes: a ring-shaped or asemi-ring-shaped contact detection member that slides along the needleat an instant when the needle is inserted; and a third switch that isoperated by the sliding of the contact detection member.

Therefore, it is possible to detect that the needle is contacting theskin with a simple structure.

According to a thirty-eighth aspect of the present invention, in theadministration instrument for medical use of the thirty-third aspect,the needle contact detection unit includes: a third switch which is onthe same side of the skin touch portion as the needle, and is operatedduring the administration at an instant when the needle is inserted intothe skin.

Therefore, it is possible to detect that the needle is contacting theskin with a simple structure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating an administration instrumentfor medical use according to a first embodiment of the presentinvention.

FIG. 2 is a perspective view with portions cutaway of the administrationinstrument for medical use according to the first embodiment.

FIG. 3 is a perspective view illustrating a state of the administrationinstrument for medical use according to the first embodiment, which isactually grasped in a hand.

FIG. 4 is a perspective view illustrating an administration instrumentfor medical use according to a second embodiment of the presentinvention.

FIG. 5 is a cross-sectional view illustrating a part of theadministration instrument for medical use according to the secondembodiment.

FIG. 6 is a perspective detail view illustrating the administrationinstrument for medical use according to the second embodiment.

FIG. 7 is a detailed view illustrating a dimension relationship betweena needle and a skin touch portion of the administration instrument formedical use according to the present invention.

FIG. 8 is a perspective view for explaining an internal structure of anadministration instrument for medical use according to a thirdembodiment of the present invention with portions cutaway.

FIG. 9 is a perspective view illustrating a positional relationshipbetween an administration button (or an injection button) and an ejectlever, for explaining an operation principle of the administrationinstrument for medical use according to the third embodiment.

FIG. 10 is a perspective view illustrating a positional relationshipbetween an administration button (or an injection button) and an ejectlever, for explaining the operation principle of the administrationinstrument for medical use according to the third embodiment.

FIG. 11 is a view illustrating a drug solution cartridge mounting stateof the administration instrument for medical use according to the thirdembodiment partially in cross section.

FIG. 12 are diagrams showing positional relationships between adetection mechanism and an injection button of the administrationinstrument for medical use according to the third embodiment when aneedle is not attached thereto.

FIG. 13 are diagrams showing positional relationships between adetection mechanism and an injection button of the administrationinstrument for medical use according to the third embodiment when aneedle is attached thereto.

FIG. 14 is a positional relationship between a detection mechanism and afix/release mechanism of the administration instrument for medical useaccording to the third embodiment when a needle is not attached thereto.

FIG. 15 is a positional relationship between a detection mechanism and afix/release mechanism of the administration instrument for medical useaccording to the third embodiment when a needle is attached thereto.

FIG. 16 is a perspective view illustrating an administration instrumentfor medical use according to a fourth embodiment of the presentinvention before attaching a needle.

FIG. 17 is a cross-sectional view illustrating a part of theadministration instrument for medical use according to the fourthembodiment.

FIG. 18 is a block diagram illustrating the administration instrumentfor medical use according to the fourth embodiment.

FIG. 19 is a block diagram for explaining the administration instrumentfor medical use according to the fourth embodiment.

FIG. 20 is a perspective view illustrating an administration instrumentfor medical use according to a fifth embodiment of the presentinvention.

FIG. 21 is a cross-sectional view illustration a part of theadministration instrument for medical use according to the fifthembodiment.

FIG. 22 is a perspective view illustrating a variation of theadministration instrument for medical use according to the fifthembodiment.

FIG. 23 is a cross-sectional view illustrating a part of the variationof the administration instrument for medical use.

FIG. 24 is a perspective view illustrating a conventional administrationinstrument for medical use.

FIG. 25 is a perspective view illustrating another conventionaladministration instrument for medical use.

FIG. 26 is a front view illustrating the conventional administrationinstrument for medical use.

FIG. 27 is a top view illustrating the conventional administrationinstrument for medical use partially in cross section.

FIG. 28 is a block diagram for explaining the conventionaladministration instrument for medical use.

FIG. 29 is a cross-sectional view illustrating a means for detectingcompletion of administration in the conventional administrationinstrument for medical use.

FIG. 30 is a cross-sectional view illustrating a means for detecting theamount of an injection in the conventional administration instrument formedical use.

FIG. 31 is a side view illustrating a means for detecting the amount ofan injection in the conventional administration instrument for medicaluse.

FIG. 32 is a block diagram for explaining the conventionaladministration instrument for medical use.

FIG. 33 is a perspective view showing an operating state of theconventional administration instrument for medical use.

FIG. 34 is a perspective view showing another operating state of theconventional administration instrument for medical use.

DETAILED DESCRIPTION OF THE INVENTION Embodiment 1

An administration instrument according to the first embodiment isconstructed so that an injection button is pressed in a direction thatis different from the direction in which a needle is inserted into theskin, thereby preventing the needle from being inserted deeper at themanipulation of the injection button.

Hereinafter, the first embodiment will be described with reference toFIGS. 1 to 3. FIG. 1 is a perspective view illustrating an appearance ofthe administration instrument for medical use according to the firstembodiment. FIG. 2 is a perspective view illustrating an internalstructure with portion cutaway of the administration instrument formedical use according to the first embodiment. FIG. 3 shows a statewhere the administration instrument for medical use according to thefirst embodiment is actually grasped with a hand.

In FIG. 1, reference numeral 1 denotes a body of the administrationinstrument for medical use, numeral 2 denotes an injection, numeral 3denotes an injection button, numeral 4 denotes a needle, numeral 6denotes a skin touch portion, numeral 7 denotes a drug solutioncartridge, numeral 8 denotes a liquid crystal display, and numeral 9denotes an administration amount adjustment knob. Further, the injectionbutton 3 is constructed to be pressed in a direction that isapproximately perpendicular to the direction in which the needle 4 isextending. The direction of pressing the injection button 3 may bedifferent from the perpendicular direction so long as it is not parallelto the direction in which the needle 4 is extending, and may formanother angle so long as it is in a direction in which the pain of thepatient body would be alleviated.

As the procedure of carrying out the injection administration, the drugsolution cartridge 7 is initially loaded into the body 1 of theadministration instrument for medical use, the needle 4 is attachedthereto, and the administration amount adjustment knob 9 is rotatedclockwise or counterclockwise as shown by an arrow in the figure, to setthe amount of the injection 2 to be administered. Then, the needle ispointed up and the injection button 3 is pressed until the injection 2flows from the tip of the needle 4, thereby removing air. Aftercompletion of this air removal operation, the administration instrumentfor medical use is grasped in a hand 19 as shown in FIG. 3, then theneedle 4 is inserted into the skin with the skin touch portion 6 beingtouched on the skin where the injection is to be administered, and theadministration is performed with pressing the injection button 3 by aforefinger 18 in a direction shown by the arrow in FIG. 3.

Next, descriptions are given of an injection amount setting method and amechanism in which the injection 2 flows out of the needle 4 when theinjection button 3 is pressed, with reference to FIG. 2.

Initially, the injection amount setting method will be described. Theadministration amount adjustment knob 9 and the sleeve 10 are fixed inthe rotational direction, but not fixed in the sliding direction.Further, the sleeve 10 and the plunger 15 that passes through a movablepiece 14 are formed integrally. An internal thread 16 is cut inside themovable piece 14 to be engaged with the sleeve 10 within the movablepiece 14. An external thread 16 is cut on a part of the sleeve 10 thatis included in the movable piece 14 to be engaged within the movablepiece 14.

In addition, the plunger 15 is formed by a member that is different fromthe plunger 20 within the drug solution cartridge 7, and is spaced apartfrom the plunger 20. At the front end of the plunger 20, a plunger 21 isprovided which is made of rubber so as to enable the injection 2 to beforced out of the drug solution cartridge 7 and is fixed to the plunger20. Further, the amount of sliding of the movable piece 14 is alwaysmade constant by the control of a spring 17.

When the administration amount adjustment knob 9 is rotated in adirection of increasing the administration amount, the plunger 15protrudes through the movable piece 14 further toward the needle. Thus,a space between the plunger 15 and a plunger 20 that is different fromthe plunger 15 is reduced. The plunger 20 does not move unless it ispushed by the plunger 15. Since the amount of slide of the movable piece14 in the case of pressing the injection button 3 is always constant,the distance by which the plunger 15 pushes the plunger 20 decides theamount of the injection administered. That is, the stroke of theinjection button at the administration is always constant regardless ofthe amount of the injection to be administered, and thus theadministration amount is decided by the amount of slide (protrudingallowance) of the plunger 15 from the movable piece 14.

Next, a description will be given of the mechanism of the injection 2coming out from the needle 4 when the injection button 3 is pushed. InFIG. 2, when the injection button 3 is pushed in the direction of anarrow, a rack 11 that is formed integrally with the injection button 3also slides in the direction of the arrow. On an end surface of the rack11 opposite to the injection button 3, a spring (injection button returnsection) 17 is provided in a form of being compressed when the injectionbutton 3 is pressed and being returned when the pressing of theinjection button 3 is stopped due to the resilience. Thus, when thepressing of the injection button 3 is stopped, the injection button 3returns to the original position due to the returning force of thespring 17.

Teeth 11 a are provided on a side of the rack 11, and a gear (firstgear) 12 is provided to engage with the teeth 11 a, and further a gear13 (second gear) is provided to engage with the gear 12. Further, teethare provided on one side of the movable piece 14 to engage with the gear13. The rack 11, the gear 12, and the gear 13 constitute a depressingforce transmitting part that transmits the depressing force of theinjection button 3 to the plunger 15 at an angle that is different fromthe direction in which the needle 4 is extending.

When the injection button 3 is pressed, the rack 11 slides, the gear 12rotates in a counterclockwise direction, and the gear 13 rotates in aclockwise direction. Then, the movable piece 14 slides together with theplunger 15 in a direction of pushing the plunger 20 and the plunger 21.Then, the plunger 21 slides in a direction of compressing the injection2 in the drug solution cartridge 7, and then the compressed injection 2is pushed out from the tip of the needle 4.

The administration instrument for medical use according to the firstembodiment transmits the force that is generated when the injectionbutton 3 is pressed by the forefinger 18 in the direction of the arrowin FIG. 3 so as not to insert the needle 4 into the skin deeper than thetime when the need is initially inserted into the skin.

Thus, according to the first embodiment, it is possible to prevent theforce of pressing the injection button at the administration of the drugsolution from being transmitted in a direction of inserting the needleinto the skin deeper than the initial insertion of the needle, therebyrealizing an administration of the drug solution under a stablecondition.

Embodiment 2

In the second embodiment, it is possible to slide the skin touch portionthat touches the skin of the administrator at the administration of thedrug solution, in a longitudinal direction of the needle and then fixthe same, thereby keeping the amount of the tip of the needle that isinserted into the skin constant regardless of the type or size of theneedle and alleviating the pain at the administration of the drugsolution.

Hereinafter, the second embodiment will be described with reference toFIGS. 4 to 7. FIG. 4 is a perspective view illustrating an appearance ofan administration instrument for medical use according to the secondembodiment. FIG. 5 is a cross-sectional view illustrating a part of theadministration instrument for medical use according to the secondembodiment. FIG. 6 is a perspective detail view illustrating theadministration instrument for medical use according to the secondembodiment. FIG. 7 is a detailed view showing a relationship between theneedle and the skin touch portion of the administration instrument formedical use according to the second embodiment.

In FIG. 4, reference numeral 31 denotes a body of the administrationinstrument for medical use, numeral 32 denotes an injection, numeral 33denotes an injection button, numeral 34 denotes a needle, numeral 36denotes a skin touch portion that is touched on the skin, numeral 37denotes a skin touch portion adjustment button, numeral 40 denotes askin touch width adjustment piece (skin touch area variable portion,skin touch width adjustment portion), and numeral 41 denotes a skintouch width adjustment button. The skin touch portion adjustment button37 is formed integrally with the skin touch portion 36, and can be slidin both directions shown by an arrow 43.

In FIG. 5, the skin touch portion 36 is integral with the skin touchportion adjustment button (skin touch position variable portion) 37, andthe skin touch portion adjustment button 37 has dowels (convex portions)38 and a side surface of the body 31 of the administration instrumentfor medical use has concave portions 39, as mating fixing parts, so thatthe skin touch portion 36 and the skin touch portion adjustment button37 can be stopped and fixed at a desired position.

Therefore, as shown in FIG. 4, it is possible to change the position ofthe skin touch portion 36 and the skin touch portion adjustment button37 at a position of a desired concave portion in the direction of thearrow 43 with respect to the needle 34 and fix the same, therebyachieving a desired dimensional relationship 42 between the needle 34and the skin touch portion 36 as shown in FIG. 7.

Further, in a case of using the same type of the needle 34 at everyadministration, by adjusting the dimensional relationship 42 of the skintouch portion 36 with respect to the needle 34 to its optimal positionand then fixing the same, it is possible to perform the administrationevery time under the same condition, and make the length of the needle34 that is inserted into the skin of the administrator (patient)constant, thereby realizing a highly-reliable administration.

In FIG. 6, the skin touch width adjustment piece 40 is integral with theskin touch width adjustment button 41, and is slid in the directionsshown by the arrow 44, i.e., in a downward direction in the figure toenlarge the skin touch portion 36, whereby when the administratortouches the skin touch portion 36 on the skin, it is possible to performan administration under a state where the instrument is held tightlywith great stability.

Thus, according to the second embodiment, it is possible to make thelength of the needle that is inserted into the skin constant regardlessof the type or size of the needle, change the position of the skin touchportion, and further variably increase the skin touch area, whereby theamount of the needle that is inserted into the skin does not vary evenwhen the length of the needle is different depending on the type of theneedle, and thus the administration state is stabilized, resulting in areliable administration instrument for medical use.

It is also possible that the position of the skin touch portion 36 isadjusted steplessly by enabling the skin touch portion 36 to be fixed atan arbitrary position, in place of the dowels and the concave portions.

Further, it is also possible to alleviate the pain at the injection byconstructing the internal structure in the same manner as the firstembodiment, and making the direction of the pressing of the injectionbutton different from the direction in which the needle 204 is insertedinto the skin.

Embodiment 3

The third embodiment inhibits pressing of the injection button or theadministration button when the needle is not attached to the instrumentbody, and further, also in the case of mixture-type drug solutionadministration, prevents the drug solutions from being mixed and housedwithin the instrument body when the needle is not attached to theinstrument body, thereby preventing a leakage or back-flow of the drugsolution, or cracking or rupture of the glass tube that contains thedrug solution.

Hereinafter, the third embodiment of the present invention will bedescribed with reference to FIGS. 8 to 15. FIG. 8 is a perspective viewillustrating an internal structure with portions cutaway of theadministration instrument for medical use according to the thirdembodiment. FIG. 9 is a perspective view for intelligibly explaining theoperation principle of the administration instrument for medical useaccording to the third embodiment when the needle is attached thereto.FIG. 10 is a perspective view for intelligibly explaining the operationprinciple of the instrument when the needle is not attached thereto.FIG. 11 is a cross-sectional view with portions cutaway of theadministration instrument for medical use according to the thirdembodiment, for explaining an operation of attaching a drug solutioncartridge. FIG. 12 are diagrams showing positional relationships betweena detection mechanism and an injection button of the administrationinstrument according to the third embodiment when the needle is notattached thereto. FIG. 13 are diagrams showing positional relationshipsbetween the detection mechanism and the injection button of theadministration instrument according to the third embodiment when theneedle is attached thereto. FIG. 14 is a diagram showing a positionalrelationship between a detection mechanism and a fix/release mechanismof the administration instrument for medical use according to the thirdembodiment when the needle is not attached thereto. FIG. 15 is a diagramshowing a positional relationship between the detection mechanism andthe fix/release mechanism of the administration instrument for medicaluse according to the third embodiment when the needle is attachedthereto.

In FIG. 8, the mechanism of injecting is briefly described. A drugsolution cartridge 52 is placed in the body of an administrationinstrument 66, and a disposable needle 51 is attached to the drugsolution cartridge 52. When the drug solution is administered to a humanbody, an administration amount setting knob 56 is adjusted to an amountto be administered. Since a plunger 55 is fixed to the administrationamount setting knob 56 in the rotation direction but not fixed in thesliding direction, the plunger is expandable or contractible in adirection parallel to the needle when the administration amount settingknob 56 is rotated. When the administration amount is set in thedirection of increasing the amount, the plunger 55 is moved in the samedirection as the needle toward the tip.

When an administration button 54 is depressed, an injectionbutton-integrated driving lever 57 is moved in the same direction as thedepressing of the injection button. A part of a side of the injectionbutton-integrated driving lever (injection button, rack) 57 has a gear(rack) that engages with a gear (first gear) 60. Further, a gear (secondgear) 59 engages with the gear 60 and a gear (rack) at the end portionof the plunger 55. At the end of the plunger 55, a drug solution pushingplunger 53 is provided, which contacts with the drug solution within thedrug solution cartridge 52. The injection button-integrated drivinglevel 57, the gear 60, and the gear 59 constitute a driving unit of theplunger 55.

When the injection button 54 is pressed in a direction as shown by anarrow of FIG. 8, the injection button-integrated driving lever 57rotates the gear 60 in a clockwise direction. By the rotation of thegear 60, the gear 59 is rotated in a counterclockwise direction whilemoving the plunger 55 in a longitudinal direction of the needle 51,i.e., moves the plunger 55 toward the left in FIG. 8. Then, the drugsolution pushing plunger 53 that is located at the end of the plunger 55forces the drug solution included in the drug solution cartridge 52 outof the needle 51, thereby achieving the administration.

In FIG. 9, an end portion (L-shaped end portion) 58 a of an eject lever58 is sandwiched between a resin part 82 of the needle 51 and the drugsolution cartridge 52. At this time, when the injection button 54 ispressed in the direction of the arrow, the injection button-integrateddriving lever 57 can freely move within an engagement portion 61 of theeject lever 58. The eject lever 58 and the injection button-integrateddriving lever 57 constitute an administration operation suppression unitthat suppresses the administration operation that is caused by pressingthe injection button. Further, the end portion (detection member) 58 aof the eject lever 58 is integral with the body of the eject lever 58,and accordingly when the needle 51 that is formed integrally with theresin part 82 is attached to the instrument, a stress is always appliedtoward the needle 51 due to a spring 63. The spring (spring member) 63and the eject lever 58 constitute a needle attachment detection part.

When the needle 51 is removed from the drug solution cartridge 52 asshown in FIG. 10, the part of the eject lever 58 moves toward the needle51, i.e., toward the left in FIG. 9 due to the stress of the spring 63.Then, the engagement portion 61 of the eject lever 58 is disengaged fromthe engagement portion 62 of the injection button-integrated drivinglever 57. When the injection button 54 is pressed in the direction asshown by the arrow at this time, the engagement portion 62 immediatelyhits the side of the eject lever 58, thereby preventing a free movement.That is, when the needle 51 is removed, it becomes impossible tocompletely press the injection button 54. As described above, accordingto the third embodiment, whether the needle is attached to theinstrument or not is detected at the end 58 a of the eject lever 58.

Next, a description will be given of a method of placing the drugsolution cartridge 52 in the instrument body 66 to house the same in theinstrument body 66, in a case of a drug solution cartridge fordissolving and mixing a drug and a drug solution, with reference to FIG.11.

In FIG. 11, a drug solution cartridge holding lid (retractable door) 67is raised up to a state shown by a dashed line in the figure, and thedrug solution cartridge 52 is inserted in the direction as shown by anarrow in this figure. After the insertion, the drug solution cartridgeholding lid 67 is lowered and closed. Next, the needle 51 is screwedinto a top threaded part of the drug solution cartridge 52 with a needlecap 65 being placed over.

Next, a projection 67 a is held and slid toward the administrationamounts setting knob 56. Then, a rear rubber part 70 inside the drugsolution cartridge 52 initially hits a dissolving piece 72 in theadministration instrument body 66. When the projection is further slid,the dissolving piece 72 will press the rear rubber part 70, whereby adrug solution 71 that is filled in the rear half of the cartridge movesa separation rubber 69 toward the front half of the cartridge, whichcontains a drug 68.

When the separation rubber 69 is moved up to an injection slot 77, thedrug solution 71 passes the injection slot (larger diameter part) 77,and flows into the drug 68. When the projection 67 a is held and slidfurther toward the administration amount setting knob 56, all of thedrug solution 71 flows into the cabin of the drug 68 through theinjection slot 77, whereby consequently the drug 68 and the drugsolution 71 are mixed. When the projection 67 a is held and slid furthertoward the administration amount setting knob 56, it cannot be slid moreand is fixed at a time when the rear rubber part 70 hits the separationrubber 69. This fixed structure will be described later with referenceto FIG. 15. In this state, the drug solution cartridge 52 is housedwithin the administration instrument body 66.

Next, relationships between the detection mechanism and the injectionbutton-integrated lever 57 when the needle is attached to the instrumentand when the needle is not attached thereto will be shown in FIGS. 12and 13, respectively, in detail. FIG. 12 show a state where the needleis not attached to the instrument, and FIG. 13 show a state where theneedle is attached thereto. Here, the term “needle” in descriptions ofFIGS. 12 to 15 refers to the needle 51 that is covered by a cap 65.

In FIG. 12( a), the drug solution cartridge 52 is kept at the end of asliding lever 75. The eject lever 58 is located over the sliding lever75, and is capable of freely moving in a direction parallel to theneedle attachment direction on the sliding lever 75.

FIG. 12( b) is a diagram illustrating the instrument of FIG. 12( a) whenviewed from the bottom. The sliding piece 75 has a slit 78 and a slit83, which can accommodate an eject knob 76. The eject lever 58 has aslit 73 at a position corresponding to the slit 83.

At the center of the sliding piece 75 and the eject lever 58, slits 81of the same width are provided at their corresponding positions,respectively. Further, within the slits 81, a spring 63 that can beaccommodated within the entire thickness dimension of the sliding piece75 and the eject lever 58 is provided parallel to the sliding piece 75.Besides, the spring 63 is latched inside the slit 81 and between aprojection 79 that projects from the sliding piece 75 and a projection80 that projects from the eject lever 58. At this time, the engagementportion 61 of the eject lever 58 is in such a positional relationshipthat the injection button-integrated driving lever 57 cannot freely movewithin the engagement portion 61. That it, it is in a state where theinjection button cannot be pressed.

Next, in FIG. 13, when the needle is attached to the drug solutioncartridge 52, the end 58 a of the eject lever 58 is pressed up to theend position of the sliding piece 75. Then, the spring 63 within theslit 81 is kept in compression from the state as shown in FIG. 12( b).On the other hand, the engagement portion 61 of the eject lever 58 getsin a positional relationship such that the injection button-integratedlever 57 can freely move. That is, the injection button is capable ofbeing pressed in this state.

Next, descriptions will be given of the principle that the drug solutioncartridge 52 cannot be housed within the administration instrument body66 when the needle is attached to the drug solution cartridge 52 and thecartridge 52 can be housed within the instrument body 66 when the needleis attached to the instrument, with reference to FIGS. 14 and 15.

In FIG. 14, when the needle is not attached to the drug solutioncartridge 52, the end portion 58 a of the eject lever 58 is protrudingbeyond the end of the sliding piece 75 toward the needle. At this time,the eject knob 76 that is urged by a spring (not shown) in an upwarddirection latches the sliding piece 75 so as not to move either towardthe needle or in the inverse direction in a state where the knob 76 ispassing through two slits, i.e., the slit (opening) 73 on the ejectlever 58 and the slit (opening) 83 on the sliding piece 75. Here, theeject knob 76 is placed in a direction perpendicular to the slidingpiece 75 and the eject lever 58, and is in a state of constantly beingpushed upward by the spring with respect to FIGS. 14 and 15.

In FIG. 15, when the needle is attached to the drug solution cartridge52, the end portion 58 a of the eject lever 58 is shifted to the sameposition as the end of the sliding piece 75. In the process of screwing(attaching) the needle to the drug solution cartridge 52, the innersurface of the slit 73 on the eject lever 58 pushes a sloped portion 76a of the eject knob 76 in a direction shown by an arrow, and accordinglythe eject know 76 is gradually pushed downward. When the needle isfurther screwed, the slit 73 on the eject lever 58 is moved in adirection of pushing the sloped portion 76 a of the eject knob 76further downward. Then, when the needle is completely attached to thedrug solution cartridge 52, the slit 73 of the eject lever 58 has pusheddown the end of the eject knob 76 and passed through, and the eject knob76 is within the slit 83 of the sliding piece 75, thereby latching thesliding piece 75 in a direction opposite to the arrow.

To house the drug solution cartridge 52 in the administration instrumentbody 66 under this state, the drug solution cartridge 52 that is locatedon the sliding piece 75 is slid in the direction shown by the arrowtogether with the sliding piece 75.

Practically, as described with reference to FIG. 11, the drug solutioncartridge is moved with being placed within the drug solution cartridgeholding lid 67, and only the principle has been given here.

When the drug solution cartridge 52 on the sliding piece 75 is movedtogether with the sliding piece 75 in the direction shown by the arrow,i.e., toward the right in FIG. 14, the slit 83 hits the sloped portion76 a of the eject knob 76. When the cartridge is further moved from thispoint in the direction of the arrow, the eject knob 76 is pushed by thesliding piece 75 in a downward direction, and when the sliding piece 75is moved further in the direction of the arrow, the end portion of theeject knob 76 fits into the slit 78 of the sliding piece 75, and at thesame time, latches the sliding piece 75 at that position, therebypreventing the sliding piece from being moved in a direction opposite tothe arrow.

This state is shown in FIG. 13( a). To release this state, a slide knobthat is integral with the eject knob 76 is provided outside theadministration instrument body 66, and this slide knob is forcefullypushed down lightly by a finger, thereby enabling the releasingoperation.

When two kinds of drug solutions are mixed in the administrationinstrument body, or a drug and a drug solution are dissolved and mixedas described with reference to FIG. 11, this instrument inhibits themixing because the cartridge cannot be placed within the administrationinstrument body unless the needle is attached thereto.

As described above, according to the third embodiment, the injectionbutton or the administration button cannot be pushed and the plungerthat forces the drug solution out of the instrument does not operatewhen the needle is not attached to the administration instrument, andfurther in the case of mixture-type drug administration instrument, itis impossible to perform the mixing when the needle is not attached tothe administration instrument. Therefore, when the needle is notattached to the administration instrument body, it is impossible to pushthe injection button or the administration button even if theadministrator erroneously intends to push the button, thereby preventingleakage of the drug solution or rupture of the glass tube or the like,which is caused by the erroneous operation.

Embodiment 4

According to a fourth embodiment, an alarm display is performed to alertthe administrator to carryout an air removal operation when performingthe injection with an administration instrument for medical useincluding an electronic device.

Hereinafter, the fourth embodiment will be described with reference toFIGS. 16 to 18. FIG. 16 is a perspective view illustrating an appearanceof an administration instrument for medical use according to the fourthembodiment before attaching a needle, FIG. 17 is a cross-sectional viewillustrating a part of the administration instrument for medical useaccording to the fourth embodiment, and FIG. 18 is a block diagramshowing a microprocessor 25 in the center.

In FIG. 16, numeral 102 denotes a cap for the instrument body, numeral103 denotes a body of the administration instrument for medical use,numeral 104 denotes a display, numeral 105 denotes an administrationamount setting dial, numeral 106 denotes an injection button, andnumeral 127 denotes a speaker.

Initially, a description is given of a case where the administrationinstrument for medical use is first employed. In FIGS. 16 and 17, whenthe cap 102 for the body is removed from the body 103 of administrationinstrument for medical use, a switch (first switch) 110 that is providedon the body 103 of the administration instrument for medical use isswitched from ON to OFF. At this time, function displays that aredisplayed on the display 104 are all lighted up and, after severalseconds, only the calendar, the time, and the administration amount aredisplayed.

In FIG. 17, screw parts 109 a and 109 b of the body 103 of theadministration instrument for medical use are engaged by threads,respectively. The screw parts 109 a and 109 b are rotated in a directionwhere the threads are loosen, thereby separating the body 103 of theadministration instrument for medical use into two screw units 103 a and103 b. After the separation, a drug solution cartridge is placed in thescrew unit 103 a, then the screw units 103 a and 103 b are engaged againat the screw parts 109 a and 109 b, and the screw units 103 a and 109 bare rotated in a direction of being fixed, resulting in the originaladministration instrument 103 for medical use. Then, a cartridgedetecting switch (second switch) 111 that is provided inside theadministration instrument 103 for medical use is switched from OFF toON.

When this state has been achieved, a text “Remove air” appears on thedisplay 104, and starts blinking. In synchronization with this blinking,a voice of “Remove air, please” is outputted from the speaker 127. Then,the administrator attaches the needle 101 to the instrument, turns theneedle 101 upward, and presses the injection button 106 with theinjection button 106 facing downward until the drug solution 126 comesout from the needle 101. Then, as described in the prior art, the switch113 (corresponding to the switch 413 in FIG. 32 as described as theprior art) is turned ON once and turned OFF again. This state of theswitch 113 is employed also to judge completion of the air removal, andthe microprocessor (air removal display signal generation unit) 125judges that the air removal has been completed.

Here, the above-mentioned blinking of the text of “Remove air” andannouncement by voices are continued until the microprocessor 125 judgesthe state of the switch 113 as the completion of the air removal.Further, the judgement of the states of the switches 110 and 111, and adisplay instruction and a voice announcement instruction for the display104 are carried out by the microprocessor (air removal audio signalgeneration unit) 125 of FIG. 18. That is, the microprocessor 125, thedisplay 104, and the speaker 127 constitute an air removal announcementsection. Further, in this FIG. 18, reference numeral 123 denotes acalendar for generating date information, and numeral 124 denotes aclock for generating time information.

Next, a description will be given of a state where the drug solutioncartridge 107 is already placed in the administration instrument 103 formedical use, i.e. a case of the second or following administration. Whenthe body cap 102 is removed from the administration instrument 103 formedical use, the switch 110 that is provided on the body 103 of theadministration instrument for medical use is switched from ON to OFF. Atthis time, the function displays that are displayed on the display 104are all lighted up and, after several seconds, only the calendar, thetime, and the administration amount are displayed.

Then, the text of “Remove air” is blinked on the display 104 and, insynchronization with this, the voice “Remove air, please” is outputtedfrom the speaker 127. Then, the administrator attaches the needle 101 tothe instrument, and presses the injection button 106 with facing theneedle 101 upward and the injection button 106 facing downward until thedrug solution 126 comes out of the needle 101. Then, as in the case ofthe first usage, the microprocessor 125 judges that the air removal hasbeen completed from the state of the switch 113, and then the display ofthe text “Remove air” is turned off, and further the voice announcement“Remove air, please” is stopped.

Here, the means for detecting the completion of the injection, the meansfor detecting the amount of the injection administered, the means forrecording the amount of the injection administered, and the means fordetecting the completion of the injection and the amount of theinjection administered and simultaneously recording and displaying thedetected amount of the administered injection, the date, and the timeare the same as those described in the prior art.

The display for urging the administrator to perform the air removal inthe above descriptions can be made not only by the text but also using asymbol or a figure. Further, it is also possible to urge theadministrator to perform the air removal operation by one of the displayand the voices.

As described above, according to the fourth embodiment, the text of“Remove air” is displayed on the display when the body cap that isplaced over the needle attachment part of the administration instrumentfor medical use to which the needle is attached, is removed. Therefore,it is possible to make the administrator of the drug solution aware ofthe air removal operation before the administration, thereby urging theadministrator to perform the “air removal” operation.

Embodiment 5

A fifth embodiment can solve a problem of the administration instrumentfor medical use having an electronic device, that the amount of aninjection that is preliminarily outputted at the air removal is recordedwithout being distinguished from the essential injection.

Hereinafter, the fifth embodiment will be described with reference toFIGS. 19 to 23. FIG. 19 is a block diagram illustrating anadministration instrument for medical use according to the fifthembodiment with a microprocessor 125 in the center. FIG. 20 is aperspective view illustrating an appearance of the administrationinstrument for medical use according to the fifth embodiment. FIG. 21 isa cross-sectional view illustrating apart of the administrationinstrument for medical use according to the fifth embodiment. FIG. 22 isa perspective view illustrating an administration instrument for medicaluse according to another embodiment. FIG. 23 is a cross-sectional viewillustrating a part of the administration instrument for medical useshown in FIG. 22.

In FIG. 20, reference numeral 102 denotes a needle insertion attachment,numeral 103 denotes a body of the administration instrument for medicaluse, numeral 104 denotes a display, numeral 105 denotes anadministration amount setting dial, and numeral 106 denotes an injectionbutton. The needle insertion attachment 102 is constructed to be able toslide toward the injection button 106 almost at the same time as a timewhen the needle 101 is inserted into the skin.

In FIG. 21, the needle insertion attachment 102 is constructed to beshorter than the needle in the longitudinal direction of the needle, andslides when the needle is inserted into the skin, thereby turning onswitches (third switches) 109 a and 109 b that are provided in the body.When the switches 109 a and 109 b are turned on, the microprocessor 125judges that the needle is inserted into the skin.

Further, the administration completion detection means is amicroprocessor 125 which judges a state where a switch (not shown,corresponding to the switch 113 in FIG. 18 or the switch 413 in FIG. 32as described in the prior art) is turned on once and turned off again asthe completion of the administration. That is, the microprocessor 125performs the judgement so as to record the amount of the injectionadministered, and the date and time of the administration in the memory112 only when the state of the above-mentioned switch (not shown)indicates the completion of the administration while the switches 109 aand 109 b are ON.

On the other hand, at the air removal, the needle insertion attachment102 is not operated and the switches 109 a and 109 b are remained OFFbecause the air removal is performed in the air with the needle 101facing upward and the injection button 106 facing downward. Even whenthe injection button 106 is pressed at this time and the switch 113 isturned ON once and turned OFF again, resulting in the state of thecompletion of the administration, the microprocessor 125 judges that thehistories of the amount of the injection administered, the date, and thetime are not to be recorded in the memory because the switches 109 a and109 b are OFF. Thus, there is provided an administration instrument formedical use that records the amount of the injection administered, thedate, and the time in the memory 122 as the histories only when theneedle 101 is actually inserted into the skin and the administration hasbeen completed, and does not record the histories at the air removaloperation. In this case, dependent on the shape of the needle insertionattachment, it is possible to detect the insertion of the needle evenwith one of the switches 109 a and 109 b.

FIG. 22 is a diagram illustrating an instrument in which these switch109 a and 109 b are integrated into one switch. In FIG. 22, numeral 140denotes a needle insertion detection switch (third switch), numeral 103denotes a body of the administration instrument for medical use, numeral104 denotes a display, numeral 105 denotes an administration amountsetting dial, and numeral 106 denotes an injection button. The needleinsertion detection switch 140 is provided on the same side of a skintouch portion 141 as the needle 101, the portion 141 being provided tostabilize the administration instrument body without wobbling at theadministration.

In FIG. 23, the needle insertion detection switch 140 is turned ONalmost at the same time as a time when the needle 101 is inserted intothe skin. When this needle insertion detection switch 140 is turned ON,the microprocessor 125 judges that the needle is inserted into the skin.

Further, the administration completion detection means is themicroprocessor 125 that judges a state where a switch (not shown in FIG.19, corresponding to the switch 113 in FIG. 18) is turned ON once andturned OFF again as the completion of the administration, as the switch413 in FIG. 27 described in the prior art. That is, the microprocessor(control unit) 125 makes the judgement so that the amount of theinjection administered, the date, and the time are recorded in thememory (injection amount recording unit) 122 only when the state of thenot-shown switch indicates the completion of the administration whilethe needle insertion detection switch 140 is ON.

On the other hand, at the air removal, the needle insertion detectionswitch 140 is OFF because the air removal operation is performed in theair with the needle 101 facing upward and the injection button 106facing downward. Even when the injection button 106 is pressed at thistime, and the switch 113 is turned ON once and turned OFF again,resulting in the state of the completion of the administration, themicroprocessor 125 judges that the histories of the amount of theinjection, the date, and the time are not to be recorded in the memory122 because the needle insertion detection switch 140 is OFF.

Accordingly, there is provided an administration instrument for medicaluse which records the amount of the injection administered, the date,and the time in the memory 122 as the history only when the needle isinserted in the skin and the administration has been completed, withoutrecording the history at the air removal operation. In this case, whenthe position of the needle insertion detection switch 110 is nearer tothe needle 101, the detection at a time when the needle 101 is touchedto the skin becomes more effective.

This invention is applicable to administration instruments for medicaluse that are used in performing administration of a drug solution suchas an injection, and suitable for alleviating a pain of theadministrator as well as performing the administration with stabilityand with reliability.

1. An administration instrument for medical use comprising: a bodyincluding a skin touch portion; a drug solution cartridge set in thebody and configured to store a drug solution therein; an injectionneedle configured to be detachably attached to the drug solutioncartridge; a plunger configured to perform an administration operationby forcing out the drug solution stored in the drug solution cartridgeto administer the drug solution; an injection button configured to bepressed so as to enable the plunger to perform the administrationoperation; an administration operation inhibit unit configured to detectwhether or not the injection needle is attached to the drug solutioncartridge stored in the body, configured to perform an administrationoperation of the drug solution via the plunger when the injection buttonis pressed and when the needle is attached to the drug solutioncartridge, and configured to inhibit the administration operationperformed by the plunger when the injection button is pressed and whenthe needle is not attached to the drug solution cartridge, wherein saidadministration operation inhibit unit includes an injectionbutton-integrated driving lever attached to the injection button andextending in a direction along which the injection button is pressed,and an injection lever arranged in parallel to the plunger, and having,at one end, an end portion sandwiched against the drug solutioncartridge by the injection needle; and a spring member configured topull the injection lever toward the tip of the injection needle.
 2. Theadministration instrument of claim 1 further including a Plunger drivingunit including a first rack which is disposed on a portion of theinjection button-integrated driving lever, a first gear which is engagedwith the first rack, and a second gear which is engaged with the firstgear and a second rack, the second rack being disposed in a longitudinaldirection of the plunger, said plunger driving unit configured totransmit a pressing operation of the injection button to the plunger todrive the plunger.
 3. The administration instrument for medical use ofclaim 2 wherein when the injection needle is not attached to the drugsolution cartridge so that an end portion of the injection lever is notsandwiched between the injection needle and the drug solution cartridge,the engagement portions of the injection lever and the plunger areengaged with each other due to tension in the spring member, whereby thepressing operation of the injection button is stopped to inhibit theadministration operation; and when the injection needle is attached tothe drug solution cartridge so that the end portion of the injectionlever is sandwiched between injection needle and the drug solutioncartridge, the engagement portions of the injection lever and theplunger are not engaged with each other against the tension in thespring member, whereby the injection button or the administration buttonis capable of being pressed so as to enable the administrationoperation.
 4. The administration instrument for medical use of claim 3wherein the injection needle integrally includes a resin unit thatcontacts the administration operation inhibit unit when the injectionneedle is attached to the drug solution cartridge.
 5. The administrationinstrument for medical use of claim 4 wherein when the injection needleis removed from the drug solution cartridge the resin unit is separatedfrom the administration operation inhibit unit.
 6. The administrationinstrument for medical use of claim 3 wherein the second rack includesteeth disposed on a side, extends in the same direction as the directionalong which the injection button is pressed, and has a cut-awayengagement portion in a part thereof; the first gear is configured toengage the teeth formed on the side of the second rack; and the secondgear is configured to engage the first gear, and includes teeth disposedon the plunger in a longitudinal direction, the end portion is L-shapedand the injection lever includes a cut-away engagement portion disposedat a position corresponding to the engagement portion of the secondrack.
 7. An administration operation inhibit unit for inhibiting anadministration operation that is activated by pressing an injectionbutton or an administration button when a needle is not attached to anadministration instrument, the administration operation inhibit unitcomprising: a needle attachment detection unit for detecting whether theneedle is attached to the administration instrument or not; a plungerdriving unit for driving a plunger operation of the injection button orthe administration button, the plunger including teeth disposed in alongitudinal direction of the plunger, and wherein said needleattachment detection unit engages with the plunger driving unit when theneedle is not attached to the administration instrument to inhibitoperation of the injection button or the administration button; theplunger driving unit including the injection button for administering aninjection, which is depressed by an administrator of the injection; arack including teeth formed on one side, and extending in a directionalong which the injection button or the administration button ispressed, and having a cut-away engagement portion in a part thereof; afirst gear which engages the teeth on the one side of the rack; and asecond gear which engages the first gear and the teeth disposed on theplunger, the needle attachment detection unit including an eject leverwhich is disposed parallel to the plunger, and has a L-shaped endportion sandwiched between a drug solution cartridge and the needle, onone end, and a cut-away engagement portion that is formed at a positioncorresponding to the engagement portion of the rack; and a spring memberthat pulls the eject lever toward a tip of the needle, and when theneedle is not attached to the instrument so that the L-shaped endportion is not sandwiched between the drug solution cartridge and theneedle, the engagement portions of the eject lever and the plungerengage with each other due to a tension of the spring member, therebyinhibiting the operation of the injection button or the administrationbutton.